The loss-making subsidiary of the Bouygues conglomerate, which also has interests in construction and television, said in a statement it planned to shed 1,516 jobs out of 9,000 as part of a restructuring plan aimed at ensuring "its future in an autonomous manner."
Like other mobile phone operators, Bouygues has struggled since 2012 when Free - the brainchild of tech tycoon Xavier Niel - entered the telecoms market with low-price services, setting in motion upheaval in the sector and a brutal price war that has benefited consumers.
It attempted to consolidate its position in the sector earlier this year by bidding for ailing mobile phone operator SFR, but lost out to cable and fibre-optic network operator Numericable.
The firm then held talks with Orange, formerly the French state monopoly France Telecom, and Iliad -- Free's parent company.
But Bouygues Telecom head Olivier Roussat said Wednesday those discussions had been unsuccessful, prompting a drop of around seven percent in shares in the company and in Iliad.